You might be surprised to find, however, that the first seismometer was invented in China in 132 AD by a Chinese astronomer, mathematician, engineer, and inventor called Zhang Heng. The instrument was said to resemble a wine jar six feet in diameter, with eight dragons positioned face down along the outside of the barrel, marking the primary compass directions. In each dragon’s mouth was a small bronze ball. Beneath the dragons sat eight bronze toads, with their broad mouths gaping to receive the balls. When the instrument sensed an incoming seismic wave, one of the balls would drop and the sound would alert observers to the earthquake, giving a rough indication of the earthquake’s direction of origin. The device is said to have been very accurate and could detect earthquakes from afar, and did not rely on shaking or movement in the location where the instrument was positioned. The first ever earthquake recorded by this seismograph was supposedly somewhere in the east. Days later, a rider from there reported this earthquake. Moreover, it had the most wicked ornaments. They don’t make scientific instruments like they used to! Of course, the insides of the seismometer was filled with a sensing mechanism of some sort, the contents of which have been lost in time. In all likelihood, a simple or inverted pendulum was employed, according to experts.
Answer: (11.95, 14.11)
Explanation:
Let x be a random variable that represent the number of years of education.
Given: Sample size : n= 26
Sample mean : 
Sample standard deviation : s = 3.22
Significance level : 
Degree of freedom: df = n-1 = 25
Critical t-value for 
and df = 25 will be
90% confidence interval for mean:
A 90% confidence interval for the mean number of years of education = (11.95, 14.11)
The correct answer is B) observation.
Among the four methods, the method of data collection that is involved when an individual counts the number of vehicles passing designated locations on the Los Angeles freeway system is observation.
When researchers use the method of observation to collect information, this means that a person acts as the observer, he or she is physically in the location to observe the phenomena. In this case, an individual is placed in a specific part of the freeway to observe and count the number of vehicles that cross the designated location.
